Precalculus (6th Edition)

Published by Pearson
ISBN 10: 013421742X
ISBN 13: 978-0-13421-742-0

Chapter 11 - Further Topics in Algebra - 11.3 Geometric Sequences and Series - 11.3 Exercises: 62

Answer

$-\dfrac {1}{7}$

Work Step by Step

$\sum ^{\infty }_{i=1}\left( -\dfrac {1}{5}\right) \left( -\dfrac {2}{5}\right) ^{i-1}=\dfrac {a_{1}}{1-r};a_{1}=\left( -\dfrac {1}{5}\right) \times \left( -\dfrac {2}{5}\right) ^{1-1}=-\dfrac {1}{5};r=-\dfrac {2}{5}\Rightarrow S_{\infty }=\dfrac {a_{1}}{1-r}=\dfrac {-\dfrac {1}{5}}{1-\left( -\dfrac {2}{5}\right) }=-\dfrac {1}{7}$
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.